1. Field of the Invention
The present invention relates to a molded body treating apparatus, a sealing method of a honeycomb molded body, and a method for manufacturing a cell-sealed honeycomb fired body.
2. Discussion of the Background
Particulates such as soot and the like contained in the exhaust gas expelled by the internal combustion engines of vehicles such as busses and trucks, and construction equipment and the like, have become a problem of recent, in that they cause harm to the environment and the human body. To remedy this, there are currently being proposed various kinds of honeycomb filters using a honeycomb structured body of porous ceramic as a filter for capturing particulates contained in exhaust gases, and thus purifying the exhaust gas.
Conventionally, when manufacturing a honeycomb structured body, first, ceramic powder, binder, and a liquid dispersal medium, for example, are mixed together to prepare a moist mixture. The moist mixture is then continuously extrusion molded using a die, and the extruded molded body is then cut to a prescribed length. Carrying out above manufactures a pillar-shaped honeycomb molded body.
Next, the honeycomb molded body obtained above is dried out, and afterward a plug material paste is filled into prescribed cells to carry out sealing on the cells so that a sealed state of either end portion of the cells is achieved. After the sealed state has been achieved, degreasing and firing treatments are carried out, thereby manufacturing the honeycomb fired body.
After this, a sealing material paste is applied to the side face of the honeycomb fired body, and using an adhesive, a multitude of honeycomb fired bodies is adhered together. This state of the multitude of honeycomb fired bodies being bonded together by interposing a sealing material layer (an adhesive layer) manufactures a honeycomb fired body aggregate. A cutting treatment is carried out to the achieved aggregate of honeycomb fired bodies using a cutting machine or the like, to form a ceramic block of a prescribed form, such as cylindrical or cylindroid form. Finally, sealing material paste is applied to the external circumference of the ceramic block to form a sealing material layer (a coat layer), thus completing the manufacture of the honeycomb structured body.
In the present description the term ‘end face’ is used to refer to any face of the faces constituting the external shape of either honeycomb form (that is, the honeycomb molded body, the honeycomb fired body, or the honeycomb structured body) at which cells are exposed, while the term ‘side face’ is used to refer to all faces other than the end faces.
Here, flatness on the end face of a honeycomb fired body to which sealing of the cell has been carried out to be sought in light of uniformity of the outward appearance and physical properties thereof.
In order to adjust the shape of the sealed portion of the cell which is sealed by such a plug, there is disclosed in a method for manufacturing a honeycomb structured body including a process of sealing cells by soaking end faces of a honeycomb structured body in a slurry inside of a storage container and then pressurizing the slurry to thereby seal the cells, a method for removing slurry adhered to the end faces and drying the end faces when separating the honeycomb structured body from within the storage container. See, for example, Japanese Unexamined Patent Application Publication No. 2004-290766. The contents of this publication are incorporated herein by reference in their entirety.
Here, in conventional cases in which cells intended to be sealed cannot be sealed assuredly, the honeycomb structured body is not able to fulfill its function as a filter, and because of this, sealing of the cells is carried out in a manner in which prescribed cells are sealed with an amount of plug material paste enabling assured sealing of the cells. However, if one attempts to carry out sealing of an amount of plug material paste enabling assured sealing of the cells, there arise cases in which the plug material paste comes to protrude from the cells and the protruded plug material paste adheres to edges of the cell walls.
Japanese Unexamined Patent Application Publication No. 2004-290766 describes that, on the sealed portion of the cell, it is possible to prevent the concave (so-called recesses) receding toward the interior portion of the cells or shrinking of the plugging slurry. However, the method for manufacturing a honeycomb structured body of Patent Document 1 focuses only on slurry recesses generated when separating the honeycomb structured body from within the storage container as an object of adjusting the shape of the honeycomb structured body, and while it is indeed effective in the prevention of this kind of recess the above mentioned method was not able to do anything about the state of slurry protruding to the outside of the cells.